1. Field of the Invention
The present invention relates to novel compounds with antihypertensive and diuretic activities, namely, sulfamoyl-2-benzofurancarboxylic acid derivatives. The compounds which the present invention provides are very promising as diuretic antihypertensives.
2. Prior Art
2,3-Dihydrobenzofuran-5-sulfonamide derivatives are disclosed in KOKAI 61-63671 as useful uricosuric antihypertensives.
It has been known that 2,3-dihydrobenzofuran compounds have potent uricosuric and saluretic activities. They are racemates because of the asymmetric carbon atom at the 2-position. It becomes known from recent studies that one of the enantiomers has a uricosuric activity rather than saluretic activity in comparison with the other or vice versa. A racemate resolution method, by which the objective compounds are resolved in the final stage, is disclosed in J. Med. Chem. 24, 865-873 (1981) and another method is disclosed in Japanese Patent Application No. 61-248121, by which (.+-.)-6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid of the formula: ##STR1## that is an important intermediate for those compounds, is resolved.